Liquid crystal display

ABSTRACT

Two electrodes parallel to each other are formed on one of two substrates, homeotropic alignment films are formed on the substrates and a liquid crystal material having positive dielectric anisotropy is injected between the substrates. When a voltage is applied to the two electrodes, a parabolic electric field between the electrodes drives the liquid crystal molecules. Since the generated electric field is symmetrical with respect to the boundary-plane equal distance from each of the two electrodes, the liquid crystal molecules are symmetrically aligned with respect to the boundary-plane, and the optical characteristic is compensated in both regions divided by the boundary-plane, thereby obtaining a wide viewing angle. The electric field does not exert influences on the liquid crystal molecules on the boundary-plane since the electric field on the boundary-plane is parallel to the substrates and perpendicular to the two electrodes and thus, it is perpendicular to the liquid crystal molecules. Here, the polarization of the light is changed while passing through the liquid crystal layer and as a result, only a part of the light passes through the polarizing plate The transmittance of the light can be varied by controlling the magnitude of voltage applied to the two electrodes. The alignment direction of the liquid crystal molecules is changed in both regions of a bent portion of the electrodes by forming the electrodes in the saw shape in a pixel or in by pixel, and the retardation of the light is compensated, thereby obtaining a wider viewing angle.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 10/724,703,filed on 2 Dec. 2003, now U.S. Pat. No. 6,876,419 which is acontinuation of application Ser. No. 08/971,674, filed on 17 Nov. 1997,now U.S. Pat. No. 6,704,083 which is hereby incorporated by reference inits entirety for all purposes as if fully set forth herein, and which inturn is a continuation-in-part of application Ser. No. 08/891,499, filedon 11 Jul. 1997 now U.S. Pat. No. 6,181,402. This application alsoclaims priority under U.S.C. §119 from: Korean Patent Application No.97-22308, filed on 30 May 1997; Korean Patent Application No. 97-26861,filed on 24 Jun. 1997; and Korean Patent Application No. 97-51338, filedon 7 Oct. 1997.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a liquid crystal display having a wideviewing angle.

(b) Description of the Related Art

Generally, a conventional liquid crystal display (LCD) includes twosubstrates having electrodes and liquid crystal injected therebetween.The voltage difference between the electrodes yields an electric field,and the molecules of the liquid crystal are re-arranged by the electricfield. The polarization of incident light is varies due to there-arrangement of the liquid crystal molecules.

Hereinafter, the conventional LCD is explained in detail with referenceto the accompanying drawings.

FIGS. 1A and 1B are sectional views of a conventional twisted-nematicliquid crystal display (TN-LCD). The TN-LCD in FIG. 1A includestransparent glass substrates 1 and 2 facing each other, a liquid crystallayer 7 inserted between the substrates 1 and 2, and electrodes 3 and 4formed respectively on the inner surfaces of the substrates 1 and 2, andpolarizing plates 5 and 6 for polarizing the light are attached to theouter surfaces of the glass substrates 1 and 2 respectively.

The electrode 3 of the lower substrate 1 is a pixel electrode, theelectrode 4 of the upper substrate 2 is a common electrode, anddielectric anisotropy Δ∈ of the liquid crystal layer 7 is positive.

In the absence of an electric field, the long axes of the liquid crystalmolecules 8 of the liquid crystal layer 7 are parallel to the substrates1 and 2, and the liquid crystal molecules 8 are twisted spirally fromone substrate to the other substrate.

When a power V is connected to the electrodes 3 and 4, and a sufficientelectric field is applied to the liquid crystal layer 7 in the directionof the arrow as illustrated in FIG. 1B, the long axes of the liquidcrystal molecules 8 are parallel to the direction of the electric field.This type of TN-LCD unfortunately results in having a narrow viewingangle.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a liquid crystaldisplay (LCD) having a wide viewing angle to substantially obviate theproblems associated with the related art.

An LCD according to embodiments of the present invention includes aliquid crystal material between first and second substrates, and theliquid crystal molecules are perpendicular to the two substrates. Firstand second electrodes are formed on one of the two substrates andsubstantially parallel to each other.

Alignment films for aligning molecular axes of the liquid crystalmolecules to be perpendicular to the substrates may be formed on thefirst and/or the second substrates, and the alignment films may be ormay not be rubbed.

In addition, the LCD of the present invention may further includepolarizing plates, and the polarizing directions of the polarizingplates are either parallel or perpendicular to each other.

Here, the dielectric anisotropy of the liquid crystal material may bepositive or negative, and the liquid crystal may be at least one amongpure nematic liquid crystal, chiral nematic liquid crystal and nematicliquid crystal having chiral dopants.

When voltage is applied to the two electrodes of the LCD of the presentinvention, a parabolic electric field is generated between the twoelectrodes, and the liquid crystal molecules are re-arranged in responseto the electric field.

The liquid crystal display described above is called anelectrically-induced optical compensation liquid crystal display(EOC-LCD) hereinafter.

In the EOC-LCD according to the embodiments of the present invention,the liquid crystal molecules are symmetrically aligned to the surfacewhich is equal distance from each of the electrodes. Accordingly, thephase retardation of the transmitted light is symmetrically compensated,thereby obtaining a wide viewing angle.

The electrodes are preferably bent to form a saw shape in a pixel or bypixel in order to vary the orientations of the liquid crystal molecules.

When using the cross polarizing plates, it is preferable that thepolarizing directions of the polarizing plates are neither parallel norperpendicular to the directions of the electrodes. It is more preferablethat the angle between the polarizing directions of the polarizingplates and the electrodes is 45 degrees.

The bent angle of the electrodes may be between zero and 180 degrees,but it is most preferable that the bent angle of the electrodes is 90degrees.

Additional objects and advantages of the present invention are set forthin part in the description which follows, and in part will be obviousfrom the description, or may be learned by practice of the invention.The objects and advantages of the invention will be realized andattained by means of the elements and combinations particularly pointedout in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, illustrate embodiments of the presentinvention and, together with the description, serve to explain theprinciples of the invention.

FIGS. 1A and 1B are sectional views of a conventional TN-LCD;

FIGS. 2A to 2C and 3A to 3C illustrate basic driving principles ofEOC-LCDs according to a first and a second embodiment of the presentinvention;

FIGS. 4 to 9 show the shapes of electrodes in the EOC-LCDs according tothe embodiments of the present invention;

FIG. 10 shows the arrangement of the liquid crystal molecules at (a)portion in FIG. 9;

FIG. 11 is an exploded perspective view of an LCD according to theembodiment of the present invention; and

FIGS. 12A to 12B illustrate a basic driving principle of an EIMD-LCD(electrical induced multi domain mode-LCD) according to the embodimentof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will become apparent from a studyof the following detailed description when viewed in light of drawings.

FIGS. 2A to 2C and 3A to 3C illustrate basic driving principles ofEOC-LCDs according to a first and a second embodiment of the presentinvention.

Referring to FIGS. 2 to 2C and 3A to 3C, a pair of transparent glasssubstrates 10 and 20 respectively having alignment films 90 are facingeach other. Two linear electrodes 30 and 40 parallel to each other areformed on the inner surface of the lower substrate 10 of the substrates10 and 20. The liquid crystal layer 70 is injected between thesubstrates 10 and 20. The liquid crystal molecules 80 of the liquidcrystal layer 70 are homeotropically aligned, and thus they areperpendicular to the substrates 10 and 20. The liquid crystal molecules80 may have a pre-tilt angle with respect to the substrates 10 and 20.The electrodes 30 and 40 may be transparent or opaque conductivematerial. Two polarizing plates 50 and 60, which polarize the incidentlight, are attached to the outer surfaces of the glass substrates 10 and20 respectively.

One of the two electrodes 30 and 40 is a pixel electrode for receivingdata signals, and the other is a common electrode for receiving a commonsignal. Each pixel electrode is connected to a terminal of a switchingdevice, such as a thin film transistor, formed in each pixel.

Although the dielectric anisotropy Δ∈ of the liquid crystal layer 70 maypreferably be positive, it may be negative. The liquid crystal materialmay be at least one among nematic liquid crystal, chiral nematic liquidcrystal and nematic liquid crystal having left-handed or right-handedchiral dopants.

Either or both alignment films 90 may be rubbed so that the liquidcrystal molecules 80 may be tilted in a predetermined direction in thepresence of an electric field. However, none of the alignment films 90may be rubbed. The rubbing direction is arbitrary and, however, it ispreferable to rub the two alignment films in opposite directions whenboth of them are rubbed.

The polarizing directions of the polarizing plates 50 and 60 are eitherparallel to or perpendicular to each other.

It is preferable that the width of the electrodes 30 and 40 lies between1 and 10 μm, that the distance between the two electrodes 30 and 40 liesbetween 2 and 20 μm, and that the thickness of the liquid crystal layer70 is in the range between 1 and 15 μm.

In FIGS. 2A to 2C, the liquid crystal material is pure nematic liquidcrystal which has positive dielectric anisotropy, and the alignmentlayers 90 are not rubbed or they are rubbed in a direction perpendicularto the electrodes 30 and 40. In FIGS. 3A to 3C, the liquid crystalmaterial is either nematic liquid crystal having chiral dopants andpositive anisotropy or chiral nematic liquid crystal having positiveanisotropy. Even though the liquid crystal material is a pure nematicliquid crystal, in case that the alignment layers are rubbed in adirection which is not perpendicular to the electrodes 30 and 40, thearrangement of the liquid crystal molecules 80 is similar to that inFIGS. 3 b and 3C.

As shown in FIGS. 2A and 3A, in the absence of the electric field, theliquid crystal molecules 80 of the liquid crystal layer 70 areperpendicular to the substrates 10 and 20 due to the aligning force ofthe alignment films 90.

The light passing though the polarizing plate or polarizer 50 attachedto the lower substrate 10 passes through the liquid crystal layer 70without changing its polarization. The light passes through thepolarizing plate or analyzer 60 attached to the upper substrate 2 if thepolarizing directions of the polarizer 50 and the analyzer 60 areparallel to each other. However, the light is blocked by the analyzer 60if the polarizing directions of the polarizer 50 and the analyzer 60 areperpendicular to each other.

FIGS. 2B and 3B show arrangements of the liquid crystal molecules 80when sufficient electric field is applied, and FIGS. 3C and 4C areelevational views thereof. The electric field at a boundary-plane C-Cconsisting of the points equal distance from each of the two electrodes30 and 40 is substantially parallel to the two substrates 10 and 20 andis perpendicular to the two electrodes 30 and 40. As the electric fieldmoves away from the boundary plane and moves toward of the electrodes 30and 40, it curves gradually more downward. That is, the electric fieldassumes a downward parabolic shape. However, the horizontal component ofthe electric field is perpendicular to the electrodes 30 and 40.

The long axes of the liquid crystal molecules 80 is to be aligned alongthe direction of the electric field since the liquid crystal materialhas positive dielectric anisotropy. However, the liquid crystalmolecules 80 adjacent to the substrates 10 and 20 maintain theiroriginal orientation, in which they are aligned perpendicular to thesubstrates 10 and 20, since the aligning force of the alignment film 90is stronger than the force due to the electric field. Accordingly, theliquid crystal molecules change their tilt angles to balance the forceof the electric field and the aligning force when the pure nematicliquid crystal material is used.

In addition, the liquid crystal layer 70 between the two electrodes 30and 40 has at least two adjacent regions divided by the boundary planeC-C. The liquid crystal molecules 80 in a region are aligned in the samedirection, and the liquid crystal molecules 80 in the two regions arealigned symmetrically with respect to the boundary pane C-C since theelectric field between the two electrodes 30 and 40 has the parabolicshape as a whole having an apex on the boundary plane C-C.

Accordingly, as shown in FIGS. 2B and 2C, a viewing angle in thedirection perpendicular to the electrodes 30 and 40 is enlarged sincethe phase retardation of the light passing through the liquid crystallayer 70 is symmetrically compensated. The viewing angle in thedirection parallel to the electrodes 30 and 40 is also enlarged sincethe reactive index in the direction of short axes of the liquid crystalmolecules 80 has little variation.

On the other hand, since the electric field at the boundary plane C-C isformed parallel to the substrates 10 and 20, and thus perpendicular tothe long axes of the liquid crystal molecules 80, the liquid crystalmolecules 80 on the boundary-plane do not rotate.

Next, as shown in FIGS. 3B and 3C, the behaviors of the liquid crystalmolecules becomes different when the chiral nematic liquid crystal orthe nematic liquid crystal having chiral dopant is used instead of thepure nematic liquid crystal. As those in FIGS. 2B and 2C, the liquidcrystal molecules 80 on the boundary plane C-C do not rotate. However,the arrangement of the liquid crystal molecules 80 in both sides of theboundary plane C-C is not completely symmetrical to each other since thelong axes of the liquid crystal molecules 80 are changed by the forceresulting from chirality as well as the force resulting from theelectric field and the alignment force.

That is, in FIG. 2C, the long axes of the liquid crystal molecules 80are aligned perpendicularly to the electrodes 30 and 40 when viewed fromthe top, but, in FIG. 3C, the liquid crystal molecules 80 in both sidesof the boundary plane C-C may be twisted either counterclockwise orclockwise with respect to the adjacent molecules. Accordingly, the wideviewing angle is obtained in both parallel and perpendicular directionsto the electrodes 30 and 40.

In the above state, the polarization of the polarized light passingthrough the polarizer 50 varies according to the twist and tilt of theliquid crystal molecules as the light passes through the liquid crystallayer 70. Then, a component of the light having a polarization parallelto the analyzer passes through the analyzer 60.

In the above two cases, the polarization can be rotated by ninetydegrees by controlling the dielectric anisotropy, the gap between thetwo substrates 10 and 20, or the pitch of the liquid crystal molecules80. In this case, if the polarizing directions of the polarizer 50 andthe analyzer 60 are parallel to each other, the light is blocked out bythe analyzer 60. If the polarizing directions of the polarizer 50 andthe analyzer 60 are perpendicular to each other, the light passesthrough the analyzer 60.

To summarize, the liquid crystal molecules 80 are arranged symmetricallywith respect to the boundary plane C-C in the EOC-LCD according to theembodiments of the present invention. Accordingly, the light transmittedin the direction of A and the light transmitted in the direction of B inFIGS. 2B and 3B pass through paths made by the similar arrangement ofthe liquid crystal molecules 80. Accordingly, the wide viewing angle canbe obtained since the retardation with respect to the passing light isformed almost in the same way.

The structure and the arrangement of the electrodes may be varied invarious ways in the above type of LCD, and, however, it is preferable toform the electrodes having a saw shape in a pixel or by pixel asillustrated in FIGS. 4 and 9, whereby a very good display characteristiccan be obtained. Hereinafter, the structure and the arrangement of theelectrodes in rectangular pixels will be explained in detail.

As shown in FIGS. 4 and 5, a first electrode line 32, which is a commonelectrode line, and a second electrode line 42, which is a pixelelectrode line, are parallel to each other in each pixel.

In the embodiment of the present invention illustrated in FIG. 4, thefirst and the second electrode lines 32 and 42 facing each other in eachpixel are extended in alternate directions along the rows of the pixels,for example, the first in the transverse direction, the second in thelongitudinal direction, the third in the transverse direction, and soon. On the contrary, the electrode lines 32 and 42 are extended in thesame direction along the columns of the pixels. First and secondelectrodes 33 and 43 parallel to each other are arranged alternately,and extended from the first and the second electrode lines 32 and 42respectively.

In the embodiment of the present invention illustrated in FIG. 5, thefirst and the second electrode lines 32 and 42 facing each other inparallel are extended in alternate directions along both the rows andthe columns of the pixels, and thus electrode lines in all pixelsadjacent to a pixel having a transverse electrode line are extended inthe longitudinal direction.

In the embodiments of the present invention illustrated in FIGS. 6 and7, the first electrode and the second electrode are extended diagonallyin each pixel.

As illustrated in FIGS. 6 and 7, the first electrode lines 32, have theshape of either

which is made by extending the electrode lines to the transverse and thelongitudinal directions from one peak in the pixels. The secondelectrode lines 42 have the shape of either

which is made by extending electrode lines to the transverse and thelongitudinal directions from another vertex facing the above mentionedvertex diagonally. The first and the second electrodes 32 and 33 have arotational symmetry with respect to a diagonal of a pixel.

The first electrodes 33 and the second electrodes 43 parallel to eachother are extended from the first electrode line 32 and the secondelectrode line 42 in directions making angles with the electrode lines32 and 33, and they are arranged alternately. In the embodiment of thepresent invention illustrated in FIG. 6, the electrodes 33 and 43 in apixel makes an angle with the electrodes 33 and 34 in the adjacentpixels along the rows of the pixels, and the first electrode 33 and thesecond electrode 43 in the same column are extended in the samedirection. On the other hand, in the embodiment of the present inventionillustrated in FIG. 7, the electrodes 33 and 43 in a pixel makes anangle with those in the adjacent pixels along both the rows and thecolumns of the pixel.

In the embodiment of the present invention as illustrated in FIG. 8, thepixels have parallelogram shapes.

As illustrated in FIG. 8, first electrode lines 32, which are the commonelectrode lines, and second electrode lines 42, which are the pixelelectrode lines, are parallel to each other and extended in thetransverse direction. The first electrodes 33 and the second electrodes43, connected respectively to the first and the second electrode lines42 and 43 are arranged alternately and parallel to each other, and theirextending directions are neither the transverse direction nor thelongitudinal direction. The lengths of the electrodes are the same, andthus the pixels have parallelogram shapes. The electrodes 33 and 43 in arow are extended in the same direction, and, however, the electrodes 33and 43 in adjacent rows are extended in the different directions. Forexample, as shown in FIG. 8, the electrodes 33 and 43 in the first roware slanted to the right with respect to the directions perpendicular tothe electrode lines 32 and 42, but those in the second row are slantedto the left. Accordingly, the first electrode 33 and the secondelectrode 43 form a saw shape along the rows of the pixel.

In the embodiment of the present invention as illustrated in FIG. 9, thepixel itself has the saw shape.

As illustrated in FIG. 9, each pixel has the saw shape, a centralportion of the pixel being bent. A first electrode line 32, which is thecommon electrode, and a second electrode line 42, which is the pixelelectrode, are formed parallel to each other in each pixel, and theyface each other.

The first electrodes 33 and the second electrodes 43 connectedrespectively to the first electrode line 32 and the second electrodeline 42 are alternately arranged and they are parallel to each other.The first electrodes 33 and the second electrodes 43 have the saw shape,the central portion in the pixel being bent.

FIG. 10 is an enlarged view of a bent portion (a) of the electrodes inFIG. 8.

The liquid crystal molecules 80 are driven by the electric field havinga parabolic shape when voltage is applied to the first electrode 33 andthe second electrode 43. As shown in FIG. 10, a projection of the liquidcrystal molecules 80 onto the substrate is perpendicular to theelectrodes 33 and 34, and the liquid crystal molecules 80 rise upward inthe head of an arrow in FIG. 10. Accordingly, the arrangement of theliquid crystal molecules 80 is symmetrical with respect to the boundaryplane C-C. Two pairs of two regions, which are symmetrically aligned onthe basis of the boundary plane C-C at both sides of the bent portion,are formed since the electrodes 33 and 43 are bent in the saw shape.Therefore, the LCD has four regions, in which alignments of the liquidcrystal molecules 80 are different from one another.

The polarizing directions of the polarizing plates 50 and 60 may be anydirections, but is preferable that they are neither parallel to norperpendicular to a part of the first and the second electrodes 33 and43. In particular, the display characteristic is the best when the angleformed by the polarizing directions of the polarizing plates 50 and 60and the electrodes 33 and 43 is 45 degrees.

The bent angle of the first and the second electrodes 33 and 43 havingthe saw shape may be within a range between 0 to 180 degrees, and it isrelated to the polarizing directions of the polarizing plates 50 and 60.The bent angle of the electrodes 33 and 43 is 90 degrees when the angleformed by the polarizing directions of the polarizing plates 50 and 60and the electrodes 33 and 43.

In order to compensate residual phase difference due to the retardationof light, a phase difference compensation film may be attached to theoutside of the LCD in accordance with the embodiments of the presentinvention.

FIG. 11 is an exploded perspective view of an LCD according to theembodiment of the present invention, to which compensation films areattached.

As illustrated in FIG. 11, compensation films 110 are attached between aliquid crystal cell 100 and polarizing plates 50 and 60. The LCD in FIG.11 has two sheets of the compensation films 110, each being attachedbetween each side of the liquid crystal cell 100 and each polarizingplate 50 or 60 respectively. However, the LCD may have only acompensation film 110 being attached between either of the two sides ofthe liquid crystal cell and either of the polarizing plates 50 and 60,and the LCD may have at least three sheets of compensation films. Auniaxial or a biaxial compensation film may be used as the compensationfilm, and a combination of the uniaxial compensation film and thebiaxial compensation film may be used.

The electrodes 33 and 43 having the saw shape illustrated in FIGS. 4 to9 may be adapted to the LCDs of another mode in which the liquid crystalmaterial is driven by the two electrodes parallel to each other. Forexample, it can be adapted to an in-plane switching (IPS) mode or anelectrical induced multi domain (EIMD) mode.

Hereinafter, the IPS-LCD and EIMD-LCD are explained in detail.

In the IPS-LCD, the two electrodes, being parallel to each other, areformed on one substrate as the EOC-LCD. Here, the dielectric anisotropyΔ ∈ of the liquid crystal material may be positive or negative.

In the absence of the electric field, the long axes of the liquidcrystal molecules are parallel to the substrates 10 and 20, and arealigned in the direction being parallel to or making a predeterminedangle with the electrodes 33 and 43. When sufficient electric field isapplied to the liquid crystal material, the electric field, which issubstantially parallel to the substrate, is generated, whereby the longaxes of the liquid crystal molecules 80 in the central portion of theliquid crystal layer are aligned substantially parallel to the electricfield. However, the liquid crystal molecules 80, which are positionedfrom the substrates 10 and 20 to the central potion of the liquidcrystal layer, are spirally twisted since the liquid crystal molecules80 around the substrates 10 and 20 keep their original orientations byan aligning force.

In the EIMD-LCD, a plurality of first electrodes and second electrodes,being parallel to each other, are formed alternately on each substrate.

FIGS. 12A and 12B are schematic views of a principle of the EIMD-LCDaccording to the embodiment of the present invention.

As illustrated in FIGS. 12A and 12B, a pair of transparent glasssubstrates 10 and 20, on which alignment films 90 are formedrespectively, face each other in a parallel manner. A first linearelectrode 30 and a second linear electrode 40 parallel to each other areformed respectively on the inner surface of the substrates 10 and 20,and they are arranged alternately. The liquid crystal material isinjected between the two glass substrates 10 and 20, thereby forming aliquid crystal layer 70, and the liquid crystal molecules 80 in theliquid crystal layer 70 are aligned perpendicularly to the twosubstrates 10 and 20. In addition, the polarizing plates 50 and 60 areattached to outsides of the two substrates 10 and 20 respectively.

It is preferable that the dielectric anisotropy Δ∈ of the liquid crystalmaterial of the liquid crystal layer 70 is positive, however, thedielectric anisotropy Δ∈ may be negative.

As illustrated in FIG. 12A, in the absence of the electric field, theliquid crystal molecules 80 in the liquid crystal layer 70 is alignedperpendicularly to the two substrates 10 and 20 by the aligning force ofthe alignment film 90.

FIGS. 12A and 12B are views of the EIMD-LCD when a sufficient electricfield is present in the LCD. The electric field having the inclinationangle with respect to the direction perpendicular to the two substrates10 and 20 is formed by the first and the second electrodes 30 and 40when the sufficient electric field is present in the LCD. This electricfield is formed symmetrically with respect to a plane which isperpendicular to the two substrates 30 and 40 and passes through the twoelectrodes 30 and 40. In case of a nematic liquid crystal materialhaving positive dielectric anisotropy, the long axes of the liquidcrystal molecules 80 is aligned along the direction of the electricfield due to the electric field having the above-mentioned inclinationdirection.

In the above-mentioned IPS-LCD and EIMD-EOC likewise the EOC-LCD, theelectrodes 30 and 40 are formed in the saw shape and the retardation ofthe light is compensated by the regions in which the inclinationdirections of the liquid crystal molecules are different from eachother, thereby obtaining the wide viewing angle.

In the liquid crystal display according to the preferred embodiment ofthe present invention, the two electrodes are formed in the twosubstrates, the liquid crystal molecules are aligned perpendicularly,and a liquid crystal director is driven by the electric field in theshape of parabola between the two electrodes. Here, the liquid crystalmolecules of the liquid crystal layer in both sides of the boundaryplane surface are symmetrically formed. Accordingly, the retardation ofthe projected light is symmetrically compensated, thereby obtaining thewide viewing angle. In addition, a wider viewing angle may be obtainedsince four regions of which the alignment directions of the liquidcrystal molecules are different from one another by forming theelectrodes in the saw shape.

Other embodiments of the invention will be apparent to the skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with the true scope and spiritof the invention being indicated by the following claims.

1. A liquid crystal display having a plurality of pixels, comprising: afirst substrate having a plurality of pixel regions; a second substratefacing the first substrate; polarizing plates attached to outer surfacesof the first and second substrates respectively; a liquid crystalmaterial injected into the gap between the first and second substrates,molecules of the liquid crystal material being initially alignedperpendicularly to the substrates; wherein each pixel region is dividedinto a plurality of domains, the domains being distinguished by anaverage alignment direction of liquid crystal molecules included thereinwhen an electric field is applied to the liquid crystal material,wherein the polarizing directions of the polarizing plates are neitherparallel nor perpendicular to at least one of the average alignmentdirections of the liquid crystal molecules of the domains, and whereineach of the pixel regions includes first and second electrodes forgenerating electric fields, each of the first and second electrodeshaving a saw shape for forming domains.
 2. The liquid crystal display ofclaim 1, wherein the first substrate includes a plurality of pixelelectrodes and the second substrate includes a common electrode.
 3. Theliquid crystal display of claim 2, wherein molecules of the liquidcrystal material have negative dielectric characteristics.
 4. The liquidcrystal display of claim 1, wherein the pixel electrode includes atleast one electrode line and a plurality of electrode fingers extendingfrom the electrode line.
 5. The liquid crystal display of claim 1,wherein the first and second electrodes are along rows of the pixelregions.
 6. The liquid crystal display of claim 5, wherein voltages ofthe first and second electrodes are at different levels from each other.7. The liquid crystal display of claim 6, wherein each of the pixelregions has four domains.
 8. The liquid crystal display of claim 1,wherein each of the pixel regions is defined by a closed shape having atleast four peripheral boundaries, wherein at least two of the peripheralboundaries meet each other to define an acute interior angle of theclosed shape.
 9. The liquid crystal display of claim 1, wherein each ofthe pixel regions is defined by a closed shape having at least fourperipheral boundaries, wherein at least two of the peripheral boundariesmeet each other to define an acute interior angle of the closed shape,and at least two peripheral boundaries meet each other to define anobtuse interior angle of the closed shape.
 10. The liquid crystaldisplay of claim 1, wherein each pixel region has a shape of anon-rectangular polygon.
 11. The liquid crystal display of claim 1,wherein each pixel region has a shape of a chevron.